Climate-driven interannual ice mass evolution in Greenland
Climate-driven interannual ice mass evolution in Greenland
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DOI：
10.1016/j.gloplacha.2011.11.005
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发表时间：
2012-02
影响因子：
3.9
通讯作者：
Inga Bergmann;G. Ramillien;F. Frappart
中科院分区：
文献类型：
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作者：
Inga Bergmann;G. Ramillien;F. Frappart
我们使用低通独立成分分析（伊卡）后处理的GRACE数据（2002-2010）从不同的官方供应商（UTCSR，JPL，GFZ）重新评估格陵兰岛的质量平衡最近一段时间，并确认目前重要的冰质量损失范围为-70和-90 Gt/年的冰盖，由于东海岸的冰川的负贡献。我们强调了格陵兰冰盖（GrIS）的质量变化的年际变化，特别是最近在2009-2010年的冰损失减速，一旦季节性周期被强烈删除的季节性趋势黄土（STL）分解。年际变化导致不同的趋势估计取决于所考虑的时间跨度。冰后反弹效应对冰量趋势估计的校正在整个冰盖上不超过8 Gt/y。我们还调查了可能的气候原因，可以解释这些冰量年际变化，因为建立了基于GRACE的质量平衡和大气/海洋平行之间的强相关性：（1）雪积累的变化，（2）定期加速沿海地区冰川崩解的温暖海水输入的影响，冰川融化产生的淡水流冷却沿海海水的反馈效应。这些结果表明，格陵兰岛的质量平衡是由沿海海面温度在时间尺度短于积累。
We re-evaluate the Greenland mass balance for the recent period using low-pass Independent Component Analysis (ICA) post-processing of the Level-2 GRACE data (2002–2010) from different official providers (UTCSR, JPL, GFZ) and confirm the present important ice mass loss in the range of −70 and −90Gt/y of this ice sheet, due to negative contributions of the glaciers on the east coast. We highlight the high inter-annual variability of mass variations of the Greenland Ice Sheet (GrIS), especially the recent deceleration of ice loss in 2009–2010, once seasonal cycles are robustly removed by Seasonal Trend Loess (STL) decomposition. Interannual variability leads to varying trend estimates depending on the considered time span. Correction of post-glacial rebound effects on ice mass trend estimates represents no more than 8Gt/y over the whole ice sheet. We also investigate possible climatic causes that can explain these ice mass interannual variations, as strong correlations between GRACE-based mass balance and atmosphere/ocean parallels are established: (1) changes in snow accumulation, and (2) the influence of inputs of warm ocean water that periodically accelerate the calving of glaciers in coastal regions and, feed-back effects of coastal water cooling by fresh currents from glaciers melting. These results suggest that the Greenland mass balance is driven by coastal sea surface temperature at time scales shorter than accumulation.